Aetna CEO: Obamacare In A 'Death Spiral' Heading Into 2018. Aetna and Humana have called off their deal amid government concerns over competition. Here's a look back at six pivotal moments that led to this. Aetna and Humana have called off their deal amid government concerns over competition.
For the plant genus, see Synapsis (plant). Synapsis (also called syndesis) is the pairing of two homologous chromosomes that occurs during meiosis. It allows matching-up of homologous pairs prior to their segregation, and possible chromosomal crossover between them. Synapsis takes place during prophase I of meiosis.
In many synapses, the presynaptic part is located on an axon, but some postsynaptic sites are located on a dendrite or soma. Astrocytes also exchange information with the synaptic neurons, responding to synaptic activity and, in turn, regulating neurotransmission.he word synapse â from the Greek synapsis (ÏÏÎ½Î¬ÏÏÎ¹Ï), meaning conjunction, in turn from ÏÏÎ½Î¬ÏÏÎµá½¶Î½ (ÏÏÎ½ (together) and á¼ÏÏÎµÎ¹Î½ (to fasten)) â was introduced in 1897 by English physiologist Michael Foster at the suggestion of English classical scholar Arthur Woollgar Verrall.